modal verbs in English grammar

ngữ pháp cơ bản về cách sử dụng động từ khuyết thiếu trong tiếng anh, bài tập thực hành giúp học sinh năm đước cách sự dụng động từ khuyết thiếu trong tiếng anh ở hiện tại và quá khứ, các lưu ý khi sử dụng động từ khuyết thiếu

GRAMMAR: MODAL VERBS

I Form and meaning:

• Modal verbs are auxiliary verbs; they are used with other main verbs

• Note FIVE important rules:

1) Two modal verbs cannot be put together ( He will can meet you) 2) Model verb + Infinitive without to (He must to meet you)

3) Modal verbs do not have third person s (He cans meet you)

4) Modal verbs do not form tense with – ing , - ed (I canned meet you)

5) Modal verbs use inversion in questions, not do/ does ( Do can I meet

you?)

II Model verb: present and future

1 Ability: can/ be able to

 can/ cannot do sth: I can swim

 be able to do sth; be able to forms tenses

Ex: Will you be able to come tomorrow?

2 Certainty and uncertainty

Will Certainty Ex: I will meet her tomorrow 100%

Must, can’t Deduction Ex: She can’t be in France I saw her today 95% - 100% Should Expectation Ex: they should be here at 6.30 80%

May, might, could Uncertainty Ex: I may not have time to finish tonight 30 – 70%

Won’t Certainty Ex: I won’t be here tomorrow. 0%

3 Obligation: must, have to

• Note: have to is not a modal verb, and has all form of have

Ex: Anna has to leave now Why does she have to go? You don’t have to do it

• Affirmative form

Must

(something is important)

Ex: You must be here by 8.00, or the bus will leave without you

Have to

(something is necessary or follows rules) Ex: At our school, we have to wear a uniform

• Negative form

Mustn’t

(something is forbidden) Ex: You mustn’t cross the road when the red light is showing

Don’t have to

(something is NOT necessary) Ex: You don’t have to turn on the central heating It’s automatic

4 Opinions and advice: should, ought to, had better

 should/ shouldn’t + V-inf(without to)

Ex: You should do your homework

 ought to/ ought not to + V-inf:

Ex: I think she ought to talk to her parents about it

Ought to has NO third person “s”, form questions and negative without do/ does

Ex: You ought to go now Ought we to tell the teacher?

 had better (not) + V-inf for strong opinions

Ex: You’d better talk to your teacher about it (short form) We’d better not forget to turn off the computer.

PRACTICE

I Underline the correct word or phrase in each sentence

1 There's someone at the door It can/must be the postman

2 Don't worry, you don't have to/mustn't pay now

3 I think you had better/would better take a pullover with you

4 Jones could/must be president if Smith has to resign

5 Sorry, I can't stay any longer I have to/might go

6 It was 5 o'clock an hour ago Your watch can't/mustn't be right

7 It's a school rule, all the pupils have to/must wear a uniform.

8 I suppose that our team must/should win, but I'm not sure.

9 Let's tell Diana She could/might not know

10 In my opinion, the government might/should do something about this.

II Rewrite each sentence using can, could, must, have to, should (including negative forms)

1 I'm sure that Helen feels really lonely -> Helen must feel really lonely

2 You're not allowed to park here

->………

3 It would be a good idea if Harry took a holiday

->………

4 I'm sure that Brenda isn't over thirty

->………

5 Do I need a different driving license for a motorbike?

->………

6 What would you advise me to do?

->………

7 Mary knows how to stand on her head

->………

8 You needn't come with me if you don't want to

->………

9 It's possible for anyone to break into this house!

->………

10 The dentist will see you soon I don't think he'll be long

->……….